Apart from more obvious signs, non-verbal gestures and other cues can also help to determine whether someone is telling the truth or not. Forbes outlines 11 ways to potentially sniff out a liar, including several phrases to watch out for.

Apart from avoiding eye contact, breaking out in a sweat, and other possible physiological triggers, Forbes says that liars may be more likely to ask you to repeat your questions than those making honest claims. Also, liars may preface their pronouncements with "to tell you the truth" and "to be perfectly honest" more so than their truth-telling counterparts. Finally, liars also tend to use pronouns like "we" and "they" as a way to "psychologically distance themselves from a lie".

You should also take note of consistently evasive answers to direct questions. According to the article, many liars haven't thought through their stories and so prefer to keep their answers short (think one-word responses) and non-specific.

Of course, not everyone using the above phrases is being dishonest and vice versa, so you should use this advice as a possible warning sign and not as a blanket rule, and judge according to the person and situation in question. Check out the full post for the other ways to potentially catch a liar in the act.